Friday 24 October 2008 19.01 EDT
First published on Friday 24 October 2008 19.01 EDT

I am very interested in the sex life of Adam and Eve - on strictly theological grounds, you understand! There is a unique form of eroticism here, in the image of the original couple innocently enjoying all the sensual delights of the Garden of Eden. Is it impious to ponder this? Is there a risk of introducing a pornographic element into the opening chapters of the Judaeo-Christian story? Or is the idea of prelapsarian (before-the-Fall) sex actually an important evangelical tool?

My interest in this question was aroused by Paradise Lost, the best known work of John Milton, who was born 400 years ago. For some strange reason, Milton is seen as a "puritan", in nervous denial about carnal matters. Anyone who has actually read Paradise Lost will laugh at this - I know of no sexier text in English literature. I don't understand why it wasn't banned.

The poem is about Adam and Eve in paradise, and Satan's dastardly plot to get them thrown out. There are extensive descriptions of their happy life before the fall - including their love life. Yes, they do it. We're not talking about coy, Jane Austen-type hinting: two sex scenes are clearly narrated, in a manner designed to excite the reader's sensual faculties.

I advise new readers to go straight to Book Four, where the core action starts. Satan spies on the happy pair as they relax after another blissful day of gardening. As they sit together, Eve, "half embracing leaned / On our first father, half her swelling breast / Naked met his under the flowing gold / Of her loose tresses hid ... " They kiss, and Satan is filled with such envious rage at the sight of "these two / Imparadised in one another's arms" that he flies off, unable to watch. But we keep watching, as they retire to their "blissful bower", say a prayer of thanks to God, and then ... well, read it for yourself. There's another sex scene in Book Eight, by the way: Adam excitedly recounts his first thrilling encounter with Eve.

Milton was not being particularly original in supposing that Adam and Eve had sex in Eden - the daring thing was to depict it so vividly. St Augustine had long ago admitted the likelihood of their innocent sex life. But he warned us against trying to imagine it. For, as fallen beings, we cannot grasp the purity of Edenic sex - we turn it dirty. "How can it be presented to human fantasy except in the likeness of the turbid lust we have tried and not of the tranquil volition we conjecture?"

CS Lewis was inclined to agree with Augustine; he thought that Milton had crossed over into dubious territory: "the poet seems to hope that when he writes 'half her swelling breast / Naked met his' we shall be able, without further assistance, to supply for Adam an experience both very like and totally unlike anything that a fallen man could possibly enjoy!"

But surely this is exactly the point, that the reader will be ambiguously excited by the pure sex. She will (if sufficiently pious) yearn for the innocence, and she also will (if sufficiently human) turn it into soft porn.

In a sense this is sacrilegious: Milton allows Adam and Eve to become sex objects. Yet it is in a good cause: the reader's acknowledgment of the gulf between them and us, which is to say our fallenness. Milton wants us to try to imagine the impossible innocence of Eden, and to admit our inability. For us, sexuality cannot be fully innocent: it is tied up with hedonistic desire, dangerous fantasy. So there is something simultaneously frustrating and exciting about imagining prelapsarian sex. And this tension is spiritually enriching.

Satan, by the way, is incapable of sex; he can only desire. He can't get no satisfaction. He is the ultimate masturbator. Humanity, in its pristine state, is therefore defined by successful, pleasurable sex. Indeed Adam and Eve's sex is better than we can entirely imagine. Milton's genius in this poem is to dare to foreground sex, to make it so theologically loaded.